The present invention relates generally to the field of packaged electrical systems. More particularly, the invention relates to an arrangement for a motor control center (MCC) providing a reduced height form factor component support and a mechanism for interconnecting the component support with line and load conductors in an enclosure.
A range of applications exist for packaged electrical and electronic components, particularly power electronic components such as those used to power loads in industrial applications. In one type of packaged system, typically referred to as an MCC, various switch gear, control devices, protective circuit devices, programmable logic controllers, motor drives, and so forth are housed in a large enclosure that may be subdivided into compartments. The enclosure is supplied with power by power buses that extend generally in a plane toward the rear of the enclosure. The individual compartments typically house associated circuitry that may be withdrawn from the enclosure for servicing and replacement. Compartmentalizing such systems greatly enhances the ability to service the system components, and also serves to isolate the system components from one another. Thus, where access or service is required for components within one compartment of the enclosure, that compartment alone may be opened and the component support withdrawn for the necessary service.
Typical MCCs include access to power bus structures at certain locations in the rear section of the enclosure. For example, there may be multiple locations in the rear of the enclosure where component supports (sometimes referred to as “buckets”) may be slid into place and plugged into the power buses. Conventional enclosures, for example, may include a dozen rows of slots through which stab contacts extend when the component supports are placed in the enclosure. However, because access to the power buses is limited, only component supports at locations corresponding to the slot locatinos are provided, with no access to the power buses at intermediate locations. Consequently, all component supports must be configured to interface with the power buses at one or the other of the access points provided by the slots.
While much of the switchgear, protective circuitry, and power control devices used in MCCs may be large and require ample space for housing them, a number of components have been substantially reduced in size in recent years. For example, certain motor starters and motor controllers are now packaged in relatively small units, substantially smaller than the volume provided by a standard compartment in an MCC enclosure. However, due to the relative universality of the enclosure designs, enclosures have not been developed that can accommodate smaller form factor compartments. In particular, even smaller components must, at present, be provided in compartments that could accommodate much larger components, resulting in a reduction in the space efficiency and power density of the overall system.
It would be advantageous, therefore, to provide an improved technique for housing electrical components in MCCs and similar systems. There is a particular need for a reduced form factor component support and compartment in such systems, as well as mechanisms for interfacing such components with existing slotted bus bar access panels.